library ieee; use ieee.std_logic_1164.all; use ieee.numeric_std.all; library work; use work.decode_types.all; use work.common.all; use work.helpers.all; use work.crhelpers.all; use work.insn_helpers.all; use work.ppc_fx_insns.all; entity execute1 is generic ( EX1_BYPASS : boolean := true; HAS_FPU : boolean := true; -- Non-zero to enable log data collection LOG_LENGTH : natural := 0 ); port ( clk : in std_ulogic; rst : in std_ulogic; -- asynchronous flush_in : in std_ulogic; busy_out : out std_ulogic; e_in : in Decode2ToExecute1Type; l_in : in Loadstore1ToExecute1Type; fp_in : in FPUToExecute1Type; ext_irq_in : std_ulogic; interrupt_in : std_ulogic; -- asynchronous l_out : out Execute1ToLoadstore1Type; fp_out : out Execute1ToFPUType; e_out : out Execute1ToWritebackType; bypass_data : out bypass_data_t; bypass_cr_data : out cr_bypass_data_t; dbg_msr_out : out std_ulogic_vector(63 downto 0); icache_inval : out std_ulogic; terminate_out : out std_ulogic; log_out : out std_ulogic_vector(14 downto 0); log_rd_addr : out std_ulogic_vector(31 downto 0); log_rd_data : in std_ulogic_vector(63 downto 0); log_wr_addr : in std_ulogic_vector(31 downto 0) ); end entity execute1; architecture behaviour of execute1 is type reg_type is record e : Execute1ToWritebackType; cur_instr : Decode2ToExecute1Type; busy: std_ulogic; terminate: std_ulogic; fp_exception_next : std_ulogic; trace_next : std_ulogic; prev_op : insn_type_t; br_taken : std_ulogic; mul_in_progress : std_ulogic; mul_finish : std_ulogic; div_in_progress : std_ulogic; cntz_in_progress : std_ulogic; log_addr_spr : std_ulogic_vector(31 downto 0); end record; constant reg_type_init : reg_type := (e => Execute1ToWritebackInit, cur_instr => Decode2ToExecute1Init, busy => '0', terminate => '0', fp_exception_next => '0', trace_next => '0', prev_op => OP_ILLEGAL, br_taken => '0', mul_in_progress => '0', mul_finish => '0', div_in_progress => '0', cntz_in_progress => '0', others => (others => '0')); signal r, rin : reg_type; signal a_in, b_in, c_in : std_ulogic_vector(63 downto 0); signal cr_in : std_ulogic_vector(31 downto 0); signal xerc_in : xer_common_t; signal valid_in : std_ulogic; signal ctrl: ctrl_t := (others => (others => '0')); signal ctrl_tmp: ctrl_t := (others => (others => '0')); signal right_shift, rot_clear_left, rot_clear_right: std_ulogic; signal rot_sign_ext: std_ulogic; signal rotator_result: std_ulogic_vector(63 downto 0); signal rotator_carry: std_ulogic; signal logical_result: std_ulogic_vector(63 downto 0); signal countzero_result: std_ulogic_vector(63 downto 0); signal alu_result: std_ulogic_vector(63 downto 0); signal adder_result: std_ulogic_vector(63 downto 0); signal misc_result: std_ulogic_vector(63 downto 0); signal muldiv_result: std_ulogic_vector(63 downto 0); signal spr_result: std_ulogic_vector(63 downto 0); signal result_mux_sel: std_ulogic_vector(2 downto 0); signal sub_mux_sel: std_ulogic_vector(2 downto 0); signal next_nia : std_ulogic_vector(63 downto 0); signal current: Decode2ToExecute1Type; signal carry_32 : std_ulogic; signal carry_64 : std_ulogic; signal overflow_32 : std_ulogic; signal overflow_64 : std_ulogic; signal trapval : std_ulogic_vector(4 downto 0); signal write_cr_mask : std_ulogic_vector(7 downto 0); signal write_cr_data : std_ulogic_vector(31 downto 0); -- multiply signals signal x_to_multiply: MultiplyInputType; signal multiply_to_x: MultiplyOutputType; -- divider signals signal x_to_divider: Execute1ToDividerType; signal divider_to_x: DividerToExecute1Type; -- random number generator signals signal random_raw : std_ulogic_vector(63 downto 0); signal random_cond : std_ulogic_vector(63 downto 0); signal random_err : std_ulogic; -- signals for logging signal exception_log : std_ulogic; signal irq_valid_log : std_ulogic; type privilege_level is (USER, SUPER); type op_privilege_array is array(insn_type_t) of privilege_level; constant op_privilege: op_privilege_array := ( OP_ATTN => SUPER, OP_MFMSR => SUPER, OP_MTMSRD => SUPER, OP_RFID => SUPER, OP_TLBIE => SUPER, others => USER ); function instr_is_privileged(op: insn_type_t; insn: std_ulogic_vector(31 downto 0)) return boolean is begin if op_privilege(op) = SUPER then return true; elsif op = OP_MFSPR or op = OP_MTSPR then return insn(20) = '1'; else return false; end if; end; procedure set_carry(e: inout Execute1ToWritebackType; carry32 : in std_ulogic; carry : in std_ulogic) is begin e.xerc.ca32 := carry32; e.xerc.ca := carry; end; procedure set_ov(e: inout Execute1ToWritebackType; ov : in std_ulogic; ov32 : in std_ulogic) is begin e.xerc.ov32 := ov32; e.xerc.ov := ov; if ov = '1' then e.xerc.so := '1'; end if; end; function calc_ov(msb_a : std_ulogic; msb_b: std_ulogic; ca: std_ulogic; msb_r: std_ulogic) return std_ulogic is begin return (ca xor msb_r) and not (msb_a xor msb_b); end; function decode_input_carry(ic : carry_in_t; xerc : xer_common_t) return std_ulogic is begin case ic is when ZERO => return '0'; when CA => return xerc.ca; when OV => return xerc.ov; when ONE => return '1'; end case; end; function msr_copy(msr: std_ulogic_vector(63 downto 0)) return std_ulogic_vector is variable msr_out: std_ulogic_vector(63 downto 0); begin -- ISA says this: -- Defined MSR bits are classified as either full func- -- tion or partial function. Full function MSR bits are -- saved in SRR1 or HSRR1 when an interrupt other -- than a System Call Vectored interrupt occurs and -- restored by rfscv, rfid, or hrfid, while partial func- -- tion MSR bits are not saved or restored. -- Full function MSR bits lie in the range 0:32, 37:41, and -- 48:63, and partial function MSR bits lie in the range -- 33:36 and 42:47. (Note this is IBM bit numbering). msr_out := (others => '0'); msr_out(63 downto 31) := msr(63 downto 31); msr_out(26 downto 22) := msr(26 downto 22); msr_out(15 downto 0) := msr(15 downto 0); return msr_out; end; -- Tell vivado to keep the hierarchy for the random module so that the -- net names in the xdc file match. attribute keep_hierarchy : string; attribute keep_hierarchy of random_0 : label is "yes"; begin rotator_0: entity work.rotator port map ( rs => c_in, ra => a_in, shift => b_in(6 downto 0), insn => e_in.insn, is_32bit => e_in.is_32bit, right_shift => right_shift, arith => e_in.is_signed, clear_left => rot_clear_left, clear_right => rot_clear_right, sign_ext_rs => rot_sign_ext, result => rotator_result, carry_out => rotator_carry ); logical_0: entity work.logical port map ( rs => c_in, rb => b_in, op => e_in.insn_type, invert_in => e_in.invert_a, invert_out => e_in.invert_out, result => logical_result, datalen => e_in.data_len ); countzero_0: entity work.zero_counter port map ( clk => clk, rs => c_in, count_right => e_in.insn(10), is_32bit => e_in.is_32bit, result => countzero_result ); multiply_0: entity work.multiply port map ( clk => clk, m_in => x_to_multiply, m_out => multiply_to_x ); divider_0: entity work.divider port map ( clk => clk, rst => rst, d_in => x_to_divider, d_out => divider_to_x ); random_0: entity work.random port map ( clk => clk, data => random_cond, raw => random_raw, err => random_err ); dbg_msr_out <= ctrl.msr; log_rd_addr <= r.log_addr_spr; a_in <= e_in.read_data1; b_in <= e_in.read_data2; c_in <= e_in.read_data3; cr_in <= e_in.cr; -- XER forwarding. To avoid having to track XER hazards, we use -- the previously latched value. Since the XER common bits -- (SO, OV[32] and CA[32]) are only modified by instructions that are -- handled here, we can just forward the result being sent to -- writeback. xerc_in <= r.e.xerc when r.e.write_xerc_enable = '1' or r.busy = '1' else e_in.xerc; busy_out <= l_in.busy or r.busy or fp_in.busy; valid_in <= e_in.valid and not busy_out and not flush_in; terminate_out <= r.terminate; current <= e_in when r.busy = '0' else r.cur_instr; -- Result mux with current.result_sel select alu_result <= adder_result when "000", logical_result when "001", rotator_result when "010", muldiv_result when "011", countzero_result when "100", spr_result when "101", next_nia when "110", misc_result when others; execute1_0: process(clk) begin if rising_edge(clk) then if rst = '1' then r <= reg_type_init; ctrl.tb <= (others => '0'); ctrl.dec <= (others => '0'); ctrl.msr <= (MSR_SF => '1', MSR_LE => '1', others => '0'); else r <= rin; ctrl <= ctrl_tmp; if valid_in = '1' then report "execute " & to_hstring(e_in.nia) & " op=" & insn_type_t'image(e_in.insn_type) & " wr=" & to_hstring(rin.e.write_reg) & " we=" & std_ulogic'image(rin.e.write_enable) & " tag=" & integer'image(rin.e.instr_tag.tag) & std_ulogic'image(rin.e.instr_tag.valid); end if; end if; end if; end process; -- Data path for integer instructions execute1_dp: process(all) variable a_inv : std_ulogic_vector(63 downto 0); variable b_or_m1 : std_ulogic_vector(63 downto 0); variable sum_with_carry : std_ulogic_vector(64 downto 0); variable sign1, sign2 : std_ulogic; variable abs1, abs2 : signed(63 downto 0); variable addend : std_ulogic_vector(127 downto 0); variable addg6s : std_ulogic_vector(63 downto 0); variable crbit : integer range 0 to 31; variable isel_result : std_ulogic_vector(63 downto 0); variable darn : std_ulogic_vector(63 downto 0); variable setb_result : std_ulogic_vector(63 downto 0); variable mfcr_result : std_ulogic_vector(63 downto 0); variable lo, hi : integer; variable l : std_ulogic; variable zerohi, zerolo : std_ulogic; variable msb_a, msb_b : std_ulogic; variable a_lt : std_ulogic; variable a_lt_lo : std_ulogic; variable a_lt_hi : std_ulogic; variable newcrf : std_ulogic_vector(3 downto 0); variable bf, bfa : std_ulogic_vector(2 downto 0); variable crnum : crnum_t; variable scrnum : crnum_t; variable cr_operands : std_ulogic_vector(1 downto 0); variable crresult : std_ulogic; variable bt, ba, bb : std_ulogic_vector(4 downto 0); variable btnum : integer range 0 to 3; variable banum, bbnum : integer range 0 to 31; variable j : integer; begin -- Main adder if e_in.invert_a = '0' then a_inv := a_in; else a_inv := not a_in; end if; if e_in.addm1 = '0' then b_or_m1 := b_in; else b_or_m1 := (others => '1'); end if; sum_with_carry := ppc_adde(a_inv, b_or_m1, decode_input_carry(e_in.input_carry, xerc_in)); adder_result <= sum_with_carry(63 downto 0); carry_32 <= sum_with_carry(32) xor a_inv(32) xor b_in(32); carry_64 <= sum_with_carry(64); overflow_32 <= calc_ov(a_inv(31), b_in(31), carry_32, sum_with_carry(31)); overflow_64 <= calc_ov(a_inv(63), b_in(63), carry_64, sum_with_carry(63)); -- signals to multiply and divide units sign1 := '0'; sign2 := '0'; if e_in.is_signed = '1' then if e_in.is_32bit = '1' then sign1 := a_in(31); sign2 := b_in(31); else sign1 := a_in(63); sign2 := b_in(63); end if; end if; -- take absolute values if sign1 = '0' then abs1 := signed(a_in); else abs1 := - signed(a_in); end if; if sign2 = '0' then abs2 := signed(b_in); else abs2 := - signed(b_in); end if; -- Interface to multiply and divide units x_to_divider.is_signed <= e_in.is_signed; x_to_divider.is_32bit <= e_in.is_32bit; x_to_divider.is_extended <= '0'; x_to_divider.is_modulus <= '0'; if e_in.insn_type = OP_MOD then x_to_divider.is_modulus <= '1'; end if; addend := (others => '0'); if e_in.insn(26) = '0' then -- integer multiply-add, major op 4 (if it is a multiply) addend(63 downto 0) := c_in; if e_in.is_signed = '1' then addend(127 downto 64) := (others => c_in(63)); end if; end if; if (sign1 xor sign2) = '1' then addend := not addend; end if; x_to_multiply.is_32bit <= e_in.is_32bit; x_to_multiply.not_result <= sign1 xor sign2; x_to_multiply.addend <= addend; x_to_divider.neg_result <= sign1 xor (sign2 and not x_to_divider.is_modulus); if e_in.is_32bit = '0' then -- 64-bit forms x_to_multiply.data1 <= std_ulogic_vector(abs1); x_to_multiply.data2 <= std_ulogic_vector(abs2); if e_in.insn_type = OP_DIVE then x_to_divider.is_extended <= '1'; end if; x_to_divider.dividend <= std_ulogic_vector(abs1); x_to_divider.divisor <= std_ulogic_vector(abs2); else -- 32-bit forms x_to_multiply.data1 <= x"00000000" & std_ulogic_vector(abs1(31 downto 0)); x_to_multiply.data2 <= x"00000000" & std_ulogic_vector(abs2(31 downto 0)); x_to_divider.is_extended <= '0'; if e_in.insn_type = OP_DIVE then -- extended forms x_to_divider.dividend <= std_ulogic_vector(abs1(31 downto 0)) & x"00000000"; else x_to_divider.dividend <= x"00000000" & std_ulogic_vector(abs1(31 downto 0)); end if; x_to_divider.divisor <= x"00000000" & std_ulogic_vector(abs2(31 downto 0)); end if; case current.sub_select(1 downto 0) is when "00" => muldiv_result <= multiply_to_x.result(63 downto 0); when "01" => muldiv_result <= multiply_to_x.result(127 downto 64); when "10" => muldiv_result <= multiply_to_x.result(63 downto 32) & multiply_to_x.result(63 downto 32); when others => muldiv_result <= divider_to_x.write_reg_data; end case; -- Compute misc_result case current.sub_select is when "000" => misc_result <= (others => '0'); when "001" => -- addg6s addg6s := (others => '0'); for i in 0 to 14 loop lo := i * 4; hi := (i + 1) * 4; if (a_in(hi) xor b_in(hi) xor sum_with_carry(hi)) = '0' then addg6s(lo + 3 downto lo) := "0110"; end if; end loop; if sum_with_carry(64) = '0' then addg6s(63 downto 60) := "0110"; end if; misc_result <= addg6s; when "010" => -- isel crbit := to_integer(unsigned(insn_bc(e_in.insn))); if cr_in(31-crbit) = '1' then isel_result := a_in; else isel_result := b_in; end if; misc_result <= isel_result; when "011" => -- darn darn := (others => '1'); if random_err = '0' then case e_in.insn(17 downto 16) is when "00" => darn := x"00000000" & random_cond(31 downto 0); when "10" => darn := random_raw; when others => darn := random_cond; end case; end if; misc_result <= darn; when "100" => -- mfmsr misc_result <= ctrl.msr; when "101" => if e_in.insn(20) = '0' then -- mfcr mfcr_result := x"00000000" & cr_in; else -- mfocrf crnum := fxm_to_num(insn_fxm(e_in.insn)); mfcr_result := (others => '0'); for i in 0 to 7 loop lo := (7-i)*4; hi := lo + 3; if crnum = i then mfcr_result(hi downto lo) := cr_in(hi downto lo); end if; end loop; end if; misc_result <= mfcr_result; when "110" => -- setb bfa := insn_bfa(e_in.insn); crbit := to_integer(unsigned(bfa)) * 4; setb_result := (others => '0'); if cr_in(31 - crbit) = '1' then setb_result := (others => '1'); elsif cr_in(30 - crbit) = '1' then setb_result(0) := '1'; end if; misc_result <= setb_result; when others => misc_result <= (others => '0'); end case; -- compute comparison results -- Note, we have done RB - RA, not RA - RB if e_in.insn_type = OP_CMP then l := insn_l(e_in.insn); else l := not e_in.is_32bit; end if; zerolo := not (or (a_in(31 downto 0) xor b_in(31 downto 0))); zerohi := not (or (a_in(63 downto 32) xor b_in(63 downto 32))); if zerolo = '1' and (l = '0' or zerohi = '1') then -- values are equal trapval <= "00100"; else a_lt_lo := '0'; a_lt_hi := '0'; if unsigned(a_in(30 downto 0)) < unsigned(b_in(30 downto 0)) then a_lt_lo := '1'; end if; if unsigned(a_in(62 downto 31)) < unsigned(b_in(62 downto 31)) then a_lt_hi := '1'; end if; if l = '1' then -- 64-bit comparison msb_a := a_in(63); msb_b := b_in(63); a_lt := a_lt_hi or (zerohi and (a_in(31) xnor b_in(31)) and a_lt_lo); else -- 32-bit comparison msb_a := a_in(31); msb_b := b_in(31); a_lt := a_lt_lo; end if; if msb_a /= msb_b then -- Comparison is clear from MSB difference. -- for signed, 0 is greater; for unsigned, 1 is greater trapval <= msb_a & msb_b & '0' & msb_b & msb_a; else -- MSBs are equal, so signed and unsigned comparisons give the -- same answer. trapval <= a_lt & not a_lt & '0' & a_lt & not a_lt; end if; end if; -- CR result mux bf := insn_bf(e_in.insn); crnum := to_integer(unsigned(bf)); newcrf := (others => '0'); case current.sub_select is when "000" => -- CMP and CMPL instructions if e_in.is_signed = '1' then newcrf := trapval(4 downto 2) & xerc_in.so; else newcrf := trapval(1 downto 0) & trapval(2) & xerc_in.so; end if; when "001" => newcrf := ppc_cmprb(a_in, b_in, insn_l(e_in.insn)); when "010" => newcrf := ppc_cmpeqb(a_in, b_in); when "011" => if current.insn(1) = '1' then -- CR logical instructions j := (7 - crnum) * 4; newcrf := cr_in(j + 3 downto j); bt := insn_bt(e_in.insn); ba := insn_ba(e_in.insn); bb := insn_bb(e_in.insn); btnum := 3 - to_integer(unsigned(bt(1 downto 0))); banum := 31 - to_integer(unsigned(ba)); bbnum := 31 - to_integer(unsigned(bb)); -- Bits 6-9 of the instruction word give the truth table -- of the requested logical operation cr_operands := cr_in(banum) & cr_in(bbnum); crresult := e_in.insn(6 + to_integer(unsigned(cr_operands))); for i in 0 to 3 loop if i = btnum then newcrf(i) := crresult; end if; end loop; else -- MCRF bfa := insn_bfa(e_in.insn); scrnum := to_integer(unsigned(bfa)); j := (7 - scrnum) * 4; newcrf := cr_in(j + 3 downto j); end if; when "100" => -- MCRXRX newcrf := xerc_in.ov & xerc_in.ca & xerc_in.ov32 & xerc_in.ca32; when others => end case; if current.insn_type = OP_MTCRF then if e_in.insn(20) = '0' then -- mtcrf write_cr_mask <= insn_fxm(e_in.insn); else -- mtocrf: We require one hot priority encoding here crnum := fxm_to_num(insn_fxm(e_in.insn)); write_cr_mask <= num_to_fxm(crnum); end if; write_cr_data <= c_in(31 downto 0); else write_cr_mask <= num_to_fxm(crnum); write_cr_data <= newcrf & newcrf & newcrf & newcrf & newcrf & newcrf & newcrf & newcrf; end if; end process; execute1_1: process(all) variable v : reg_type; variable lo, hi : integer; variable sh, mb, me : std_ulogic_vector(5 downto 0); variable bo, bi : std_ulogic_vector(4 downto 0); variable overflow : std_ulogic; variable lv : Execute1ToLoadstore1Type; variable irq_valid : std_ulogic; variable exception : std_ulogic; variable illegal : std_ulogic; variable is_branch : std_ulogic; variable is_direct_branch : std_ulogic; variable taken_branch : std_ulogic; variable abs_branch : std_ulogic; variable spr_val : std_ulogic_vector(63 downto 0); variable do_trace : std_ulogic; variable hold_wr_data : std_ulogic; variable fv : Execute1ToFPUType; begin is_branch := '0'; is_direct_branch := '0'; taken_branch := '0'; abs_branch := '0'; hold_wr_data := '0'; v := r; v.e := Execute1ToWritebackInit; v.e.redir_mode := ctrl.msr(MSR_IR) & not ctrl.msr(MSR_PR) & not ctrl.msr(MSR_LE) & not ctrl.msr(MSR_SF); v.e.xerc := xerc_in; lv := Execute1ToLoadstore1Init; fv := Execute1ToFPUInit; x_to_multiply.valid <= '0'; x_to_divider.valid <= '0'; v.mul_in_progress := '0'; v.div_in_progress := '0'; v.cntz_in_progress := '0'; v.mul_finish := '0'; spr_result <= (others => '0'); spr_val := (others => '0'); ctrl_tmp <= ctrl; -- FIXME: run at 512MHz not core freq ctrl_tmp.tb <= std_ulogic_vector(unsigned(ctrl.tb) + 1); ctrl_tmp.dec <= std_ulogic_vector(unsigned(ctrl.dec) - 1); irq_valid := '0'; if ctrl.msr(MSR_EE) = '1' then if ctrl.dec(63) = '1' then v.e.intr_vec := 16#900#; report "IRQ valid: DEC"; irq_valid := '1'; elsif ext_irq_in = '1' then v.e.intr_vec := 16#500#; report "IRQ valid: External"; irq_valid := '1'; end if; end if; v.terminate := '0'; icache_inval <= '0'; v.busy := '0'; -- Next insn adder used in a couple of places next_nia <= std_ulogic_vector(unsigned(e_in.nia) + 4); -- rotator control signals right_shift <= '1' when e_in.insn_type = OP_SHR else '0'; rot_clear_left <= '1' when e_in.insn_type = OP_RLC or e_in.insn_type = OP_RLCL else '0'; rot_clear_right <= '1' when e_in.insn_type = OP_RLC or e_in.insn_type = OP_RLCR else '0'; rot_sign_ext <= '1' when e_in.insn_type = OP_EXTSWSLI else '0'; v.e.srr1 := (others => '0'); exception := '0'; illegal := '0'; if valid_in = '1' then v.e.last_nia := e_in.nia; else v.e.last_nia := r.e.last_nia; end if; v.e.mode_32bit := not ctrl.msr(MSR_SF); v.e.instr_tag := current.instr_tag; do_trace := valid_in and ctrl.msr(MSR_SE); if valid_in = '1' then v.prev_op := e_in.insn_type; end if; -- Determine if there is any exception to be taken -- before/instead of executing this instruction if valid_in = '1' and e_in.second = '0' then if HAS_FPU and r.fp_exception_next = '1' then -- This is used for FP-type program interrupts that -- become pending due to MSR[FE0,FE1] changing from 00 to non-zero. exception := '1'; v.e.intr_vec := 16#700#; v.e.srr1(47 - 43) := '1'; v.e.srr1(47 - 47) := '1'; elsif r.trace_next = '1' then -- Generate a trace interrupt rather than executing the next instruction -- or taking any asynchronous interrupt exception := '1'; v.e.intr_vec := 16#d00#; v.e.srr1(47 - 33) := '1'; if r.prev_op = OP_LOAD or r.prev_op = OP_ICBI or r.prev_op = OP_ICBT or r.prev_op = OP_DCBT or r.prev_op = OP_DCBST or r.prev_op = OP_DCBF then v.e.srr1(47 - 35) := '1'; elsif r.prev_op = OP_STORE or r.prev_op = OP_DCBZ or r.prev_op = OP_DCBTST then v.e.srr1(47 - 36) := '1'; end if; elsif irq_valid = '1' then -- Don't deliver the interrupt until we have a valid instruction -- coming in, so we have a valid NIA to put in SRR0. exception := '1'; elsif ctrl.msr(MSR_PR) = '1' and instr_is_privileged(e_in.insn_type, e_in.insn) then -- generate a program interrupt exception := '1'; v.e.intr_vec := 16#700#; -- set bit 45 to indicate privileged instruction type interrupt v.e.srr1(47 - 45) := '1'; report "privileged instruction"; elsif not HAS_FPU and e_in.fac = FPU then -- make lfd/stfd/lfs/stfs etc. illegal in no-FPU implementations illegal := '1'; elsif HAS_FPU and ctrl.msr(MSR_FP) = '0' and e_in.fac = FPU then -- generate a floating-point unavailable interrupt exception := '1'; v.e.intr_vec := 16#800#; report "FP unavailable interrupt"; end if; end if; if valid_in = '1' and exception = '0' and illegal = '0' and e_in.unit = ALU then v.cur_instr := e_in; v.e.valid := '1'; case_0: case e_in.insn_type is when OP_ILLEGAL => -- we need two cycles to write srr0 and 1 -- will need more when we have to write HEIR illegal := '1'; when OP_SC => -- check bit 1 of the instruction is 1 so we know this is sc; -- 0 would mean scv, so generate an illegal instruction interrupt -- we need two cycles to write srr0 and 1 if e_in.insn(1) = '1' then exception := '1'; v.e.intr_vec := 16#C00#; v.e.last_nia := next_nia; report "sc"; else illegal := '1'; end if; when OP_ATTN => -- check bits 1-10 of the instruction to make sure it's attn -- if not then it is illegal if e_in.insn(10 downto 1) = "0100000000" then v.terminate := '1'; report "ATTN"; else illegal := '1'; end if; when OP_NOP | OP_DCBF | OP_DCBST | OP_DCBT | OP_DCBTST | OP_ICBT => -- Do nothing when OP_ADD => if e_in.output_carry = '1' then if e_in.input_carry /= OV then set_carry(v.e, carry_32, carry_64); else v.e.xerc.ov := carry_64; v.e.xerc.ov32 := carry_32; end if; end if; if e_in.oe = '1' then set_ov(v.e, overflow_64, overflow_32); end if; when OP_CMP => when OP_TRAP => -- trap instructions (tw, twi, td, tdi) v.e.intr_vec := 16#700#; -- set bit 46 to say trap occurred v.e.srr1(47 - 46) := '1'; if or (trapval and insn_to(e_in.insn)) = '1' then -- generate trap-type program interrupt exception := '1'; report "trap"; end if; when OP_ADDG6S => when OP_CMPRB => when OP_CMPEQB => when OP_AND | OP_OR | OP_XOR | OP_POPCNT | OP_PRTY | OP_CMPB | OP_EXTS | OP_BPERM | OP_BCD => when OP_B => is_branch := '1'; taken_branch := '1'; is_direct_branch := '1'; abs_branch := e_in.br_abs; if ctrl.msr(MSR_BE) = '1' then do_trace := '1'; end if; when OP_BC | OP_BCREG => -- read_data1 is CTR -- for OP_BCREG, read_data2 is target register (CTR, LR or TAR) -- If this instruction updates both CTR and LR, then it is -- doubled; the first instruction decrements CTR and determines -- whether the branch is taken, and the second does the -- redirect and the LR update. bo := insn_bo(e_in.insn); bi := insn_bi(e_in.insn); if e_in.second = '0' then taken_branch := ppc_bc_taken(bo, bi, cr_in, a_in); else taken_branch := r.br_taken; end if; v.br_taken := taken_branch; abs_branch := e_in.br_abs; if e_in.repeat = '0' or e_in.second = '1' then is_branch := '1'; if e_in.insn_type = OP_BC then is_direct_branch := '1'; end if; if ctrl.msr(MSR_BE) = '1' then do_trace := '1'; end if; end if; when OP_RFID => v.e.redir_mode := (a_in(MSR_IR) or a_in(MSR_PR)) & not a_in(MSR_PR) & not a_in(MSR_LE) & not a_in(MSR_SF); -- Can't use msr_copy here because the partial function MSR -- bits should be left unchanged, not zeroed. ctrl_tmp.msr(63 downto 31) <= a_in(63 downto 31); ctrl_tmp.msr(26 downto 22) <= a_in(26 downto 22); ctrl_tmp.msr(15 downto 0) <= a_in(15 downto 0); if a_in(MSR_PR) = '1' then ctrl_tmp.msr(MSR_EE) <= '1'; ctrl_tmp.msr(MSR_IR) <= '1'; ctrl_tmp.msr(MSR_DR) <= '1'; end if; -- mark this as a branch so CFAR gets updated is_branch := '1'; taken_branch := '1'; abs_branch := '1'; if HAS_FPU then v.fp_exception_next := fp_in.exception and (a_in(MSR_FE0) or a_in(MSR_FE1)); end if; do_trace := '0'; when OP_CNTZ => v.e.valid := '0'; v.cntz_in_progress := '1'; v.busy := '1'; when OP_ISEL => when OP_CROP => when OP_MCRXRX => when OP_DARN => when OP_MFMSR => when OP_MFSPR => report "MFSPR to SPR " & integer'image(decode_spr_num(e_in.insn)) & "=" & to_hstring(a_in); if is_fast_spr(e_in.read_reg1) = '1' then spr_val := a_in; if decode_spr_num(e_in.insn) = SPR_XER then -- bits 0:31 and 35:43 are treated as reserved and return 0s when read using mfxer spr_val(63 downto 32) := (others => '0'); spr_val(63-32) := xerc_in.so; spr_val(63-33) := xerc_in.ov; spr_val(63-34) := xerc_in.ca; spr_val(63-35 downto 63-43) := "000000000"; spr_val(63-44) := xerc_in.ov32; spr_val(63-45) := xerc_in.ca32; end if; else spr_val := c_in; case decode_spr_num(e_in.insn) is when SPR_TB => spr_val := ctrl.tb; when SPR_TBU => spr_val(63 downto 32) := (others => '0'); spr_val(31 downto 0) := ctrl.tb(63 downto 32); when SPR_DEC => spr_val := ctrl.dec; when SPR_CFAR => spr_val := ctrl.cfar; when SPR_PVR => spr_val(63 downto 32) := (others => '0'); spr_val(31 downto 0) := PVR_MICROWATT; when 724 => -- LOG_ADDR SPR spr_val := log_wr_addr & r.log_addr_spr; when 725 => -- LOG_DATA SPR spr_val := log_rd_data; v.log_addr_spr := std_ulogic_vector(unsigned(r.log_addr_spr) + 1); when others => -- mfspr from unimplemented SPRs should be a nop in -- supervisor mode and a program interrupt for user mode if is_fast_spr(e_in.read_reg1) = '0' and ctrl.msr(MSR_PR) = '1' then illegal := '1'; end if; end case; end if; spr_result <= spr_val; when OP_MFCR => when OP_MTCRF => when OP_MTMSRD => if e_in.insn(16) = '1' then -- just update EE and RI ctrl_tmp.msr(MSR_EE) <= c_in(MSR_EE); ctrl_tmp.msr(MSR_RI) <= c_in(MSR_RI); else -- Architecture says to leave out bits 3 (HV), 51 (ME) -- and 63 (LE) (IBM bit numbering) if e_in.is_32bit = '0' then ctrl_tmp.msr(63 downto 61) <= c_in(63 downto 61); ctrl_tmp.msr(59 downto 32) <= c_in(59 downto 32); end if; ctrl_tmp.msr(31 downto 13) <= c_in(31 downto 13); ctrl_tmp.msr(11 downto 1) <= c_in(11 downto 1); if c_in(MSR_PR) = '1' then ctrl_tmp.msr(MSR_EE) <= '1'; ctrl_tmp.msr(MSR_IR) <= '1'; ctrl_tmp.msr(MSR_DR) <= '1'; end if; if HAS_FPU then v.fp_exception_next := fp_in.exception and (c_in(MSR_FE0) or c_in(MSR_FE1)); end if; end if; when OP_MTSPR => report "MTSPR to SPR " & integer'image(decode_spr_num(e_in.insn)) & "=" & to_hstring(c_in); if is_fast_spr(e_in.write_reg) then if decode_spr_num(e_in.insn) = SPR_XER then v.e.xerc.so := c_in(63-32); v.e.xerc.ov := c_in(63-33); v.e.xerc.ca := c_in(63-34); v.e.xerc.ov32 := c_in(63-44); v.e.xerc.ca32 := c_in(63-45); end if; else -- slow spr case decode_spr_num(e_in.insn) is when SPR_DEC => ctrl_tmp.dec <= c_in; when 724 => -- LOG_ADDR SPR v.log_addr_spr := c_in(31 downto 0); when others => -- mtspr to unimplemented SPRs should be a nop in -- supervisor mode and a program interrupt for user mode if ctrl.msr(MSR_PR) = '1' then illegal := '1'; end if; end case; end if; when OP_RLC | OP_RLCL | OP_RLCR | OP_SHL | OP_SHR | OP_EXTSWSLI => if e_in.output_carry = '1' then set_carry(v.e, rotator_carry, rotator_carry); end if; when OP_SETB => when OP_ISYNC => v.e.redirect := '1'; v.e.br_offset := std_ulogic_vector(to_unsigned(4, 64)); when OP_ICBI => icache_inval <= '1'; when OP_MUL_L64 | OP_MUL_H64 | OP_MUL_H32 => v.e.valid := '0'; v.mul_in_progress := '1'; v.busy := '1'; x_to_multiply.valid <= '1'; when OP_DIV | OP_DIVE | OP_MOD => v.e.valid := '0'; v.div_in_progress := '1'; v.busy := '1'; x_to_divider.valid <= '1'; when others => v.terminate := '1'; report "illegal"; end case; -- Mispredicted branches cause a redirect if is_branch = '1' then if taken_branch = '1' then ctrl_tmp.cfar <= e_in.nia; end if; if taken_branch = '1' then v.e.br_offset := b_in; v.e.abs_br := abs_branch; else v.e.br_offset := std_ulogic_vector(to_unsigned(4, 64)); end if; if taken_branch /= e_in.br_pred then v.e.redirect := '1'; end if; v.e.br_last := is_direct_branch; v.e.br_taken := taken_branch; end if; elsif valid_in = '1' and exception = '0' and illegal = '0' then -- instruction for other units, i.e. LDST if e_in.unit = LDST then lv.valid := '1'; elsif e_in.unit = NONE then illegal := '1'; elsif HAS_FPU and e_in.unit = FPU then fv.valid := '1'; end if; -- Handling an ITLB miss doesn't count as having executed an instruction if e_in.insn_type = OP_FETCH_FAILED then do_trace := '0'; end if; end if; -- The following cases all occur when r.busy = 1 and therefore -- valid_in = 0. Hence they don't happen in the same cycle as any of -- the cases above which depend on valid_in = 1. if r.cntz_in_progress = '1' then -- cnt[lt]z always takes two cycles v.e.valid := '1'; elsif r.mul_in_progress = '1' or r.div_in_progress = '1' then if (r.mul_in_progress = '1' and multiply_to_x.valid = '1') or (r.div_in_progress = '1' and divider_to_x.valid = '1') then if r.mul_in_progress = '1' then overflow := '0'; else overflow := divider_to_x.overflow; end if; if r.mul_in_progress = '1' and current.oe = '1' then -- have to wait until next cycle for overflow indication v.mul_finish := '1'; v.busy := '1'; else -- We must test oe because the RC update code in writeback -- will use the xerc value to set CR0:SO so we must not clobber -- xerc if OE wasn't set. if current.oe = '1' then v.e.xerc.ov := overflow; v.e.xerc.ov32 := overflow; if overflow = '1' then v.e.xerc.so := '1'; end if; end if; v.e.valid := '1'; end if; else v.busy := '1'; v.mul_in_progress := r.mul_in_progress; v.div_in_progress := r.div_in_progress; end if; elsif r.mul_finish = '1' then hold_wr_data := '1'; v.e.xerc.ov := multiply_to_x.overflow; v.e.xerc.ov32 := multiply_to_x.overflow; if multiply_to_x.overflow = '1' then v.e.xerc.so := '1'; end if; v.e.valid := '1'; end if; if illegal = '1' then exception := '1'; v.e.intr_vec := 16#700#; -- Since we aren't doing Hypervisor emulation assist (0xe40) we -- set bit 44 to indicate we have an illegal v.e.srr1(47 - 44) := '1'; report "illegal"; end if; v.e.interrupt := exception; if do_trace = '1' then v.trace_next := '1'; end if; if interrupt_in = '1' then ctrl_tmp.msr(MSR_SF) <= '1'; ctrl_tmp.msr(MSR_EE) <= '0'; ctrl_tmp.msr(MSR_PR) <= '0'; ctrl_tmp.msr(MSR_SE) <= '0'; ctrl_tmp.msr(MSR_BE) <= '0'; ctrl_tmp.msr(MSR_FP) <= '0'; ctrl_tmp.msr(MSR_FE0) <= '0'; ctrl_tmp.msr(MSR_FE1) <= '0'; ctrl_tmp.msr(MSR_IR) <= '0'; ctrl_tmp.msr(MSR_DR) <= '0'; ctrl_tmp.msr(MSR_RI) <= '0'; ctrl_tmp.msr(MSR_LE) <= '1'; v.trace_next := '0'; v.fp_exception_next := '0'; end if; if hold_wr_data = '0' then v.e.write_data := alu_result; else v.e.write_data := r.e.write_data; end if; v.e.write_reg := current.write_reg; v.e.write_enable := current.write_reg_enable and v.e.valid and not exception; v.e.rc := current.rc and v.e.valid and not exception; v.e.write_cr_data := write_cr_data; v.e.write_cr_mask := write_cr_mask; v.e.write_cr_enable := current.output_cr and v.e.valid and not exception; v.e.write_xerc_enable := current.output_xer and v.e.valid and not exception; bypass_data.tag.valid <= current.instr_tag.valid and current.write_reg_enable and v.e.valid; bypass_data.tag.tag <= current.instr_tag.tag; bypass_data.data <= v.e.write_data; bypass_cr_data.tag.valid <= current.instr_tag.valid and current.output_cr and v.e.valid; bypass_cr_data.tag.tag <= current.instr_tag.tag; for i in 0 to 7 loop if v.e.write_cr_mask(i) = '1' then bypass_cr_data.data(i*4 + 3 downto i*4) <= v.e.write_cr_data(i*4 + 3 downto i*4); else bypass_cr_data.data(i*4 + 3 downto i*4) <= cr_in(i*4 + 3 downto i*4); end if; end loop; -- Outputs to loadstore1 (async) lv.op := e_in.insn_type; lv.nia := e_in.nia; lv.instr_tag := e_in.instr_tag; lv.addr1 := a_in; lv.addr2 := b_in; lv.data := c_in; lv.write_reg := e_in.write_reg; lv.length := e_in.data_len; lv.byte_reverse := e_in.byte_reverse xnor ctrl.msr(MSR_LE); lv.sign_extend := e_in.sign_extend; lv.update := e_in.update; lv.xerc := xerc_in; lv.reserve := e_in.reserve; lv.rc := e_in.rc; lv.insn := e_in.insn; -- decode l*cix and st*cix instructions here if e_in.insn(31 downto 26) = "011111" and e_in.insn(10 downto 9) = "11" and e_in.insn(5 downto 1) = "10101" then lv.ci := '1'; end if; lv.virt_mode := ctrl.msr(MSR_DR); lv.priv_mode := not ctrl.msr(MSR_PR); lv.mode_32bit := not ctrl.msr(MSR_SF); lv.is_32bit := e_in.is_32bit; lv.repeat := e_in.repeat; lv.second := e_in.second; -- Outputs to FPU fv.op := e_in.insn_type; fv.nia := e_in.nia; fv.insn := e_in.insn; fv.itag := e_in.instr_tag; fv.single := e_in.is_32bit; fv.fe_mode := ctrl.msr(MSR_FE0) & ctrl.msr(MSR_FE1); fv.fra := a_in; fv.frb := b_in; fv.frc := c_in; fv.frt := e_in.write_reg; fv.rc := e_in.rc; fv.out_cr := e_in.output_cr; -- Update registers rin <= v; -- update outputs l_out <= lv; e_out <= r.e; e_out.msr <= msr_copy(ctrl.msr); fp_out <= fv; exception_log <= exception; irq_valid_log <= irq_valid; end process; e1_log: if LOG_LENGTH > 0 generate signal log_data : std_ulogic_vector(14 downto 0); begin ex1_log : process(clk) begin if rising_edge(clk) then log_data <= ctrl.msr(MSR_EE) & ctrl.msr(MSR_PR) & ctrl.msr(MSR_IR) & ctrl.msr(MSR_DR) & exception_log & irq_valid_log & interrupt_in & "000" & r.e.write_enable & r.e.valid & (r.e.redirect or r.e.interrupt) & r.busy & flush_in; end if; end process; log_out <= log_data; end generate; end architecture behaviour;